The photolithographic process, which is one of the processes for manufacturing microdevices such as semiconductor devices and liquid crystal display devices, uses an exposure apparatus that projects the image of a pattern formed on a mask onto a photosensitive substrate. This exposure apparatus comprises a mask stage that supports a mask as well as a substrate stage that supports a substrate, and projects an image of the pattern of the mask onto the substrate through a projection optical system while successively moving the mask stage and the substrate stage. In the field of microdevice fabrication, there is demand to increase the fineness of the patterns formed on substrates in order to increase device density. There is also demand to increase the resolution of exposure apparatuses in order to meet this need; furthermore, as one means to achieve that increased resolution, an immersion exposure apparatus has been proposed that performs an exposure process in a state wherein a liquid, which has a refractive index higher than that of a gas, is filled between the projection optical system and the substrate, as disclosed in Patent Document 1 below.
Patent Document 1 PCT International Publication No. WO99/49504
Patent Document 2 Japanese Unexamined Patent Application, Publication No. 2004-289127